In 1997, Intel announced that it would license the Rambus technology for use on its future motherboards, thus making it the likely de facto standard for memory architectures. However, a consortium of computer vendors is working on an alternative memory architecture called SyncLink DRAM (SLDRAM).

RDRAM is already being used in place of VRAM in some graphics accelerator boards. As of late 1999, Intel has been using RDRAM in its Pentium III Xeon processors and more recently in its Pentium 4 processors. Intel and Rambus are also working a new version of RDRAM, called nDRAM, that will support data transfer speeds at up to 1,600 MHz.

Synchronous DRAM (SDRAM) 
Excellent overview of SDRAM, along with details on RDRAM and VRAM memory and technologies. This page is from "The PC Guide".

Rambus home page
Corporate web site for Rambus, Inc., developer of Rambus DRAM.

SDRAM vs. RDRAM, Facts and Fantasy
In-depth analysis of Rambus' RDRAM aims to find its technological advantages and disadvantages, as well as reach a verdict on the SDRAM vs. RDRAM issue.